PCR-based screening for the most prevalent alpha 1 antitrypsin deficiency mutations (PI S, Z, and Mmalton) in COPD patients from Eastern Tunisia.

It is generally agreed that the protease inhibitor (PI) alleles PI*S (Val264Glu) and PI*Z (Lys342Glu) are the most common alpha 1 antitrypsin deficiency variants worldwide, but the PI*Mmalton allele (ΔPhe52) prevails over these variants in some Mediterranean regions. In eastern Tunisia (Mahdia), we screened 100 subjects with chronic obstructive pulmonary disease for these variants. The PI*S and PI*Z alleles were genotyped by the previously described SexAI/Hpγ99I RFLP-PCR. We provide here a new method for PI*Mmalton genotyping using mismatched RFLP-PCR. These methods are suitable for routine clinical application and can easily be reproduced by several laboratories, since they do not require extensive optimization, unlike the previously described bidirectional allele-specific amplification PCR for PI*Mmalton genotyping. Our results were in agreement with previous reports from central Tunisia (Kairouan), suggesting that the PI*Mmalton mutation is the most frequent alpha 1 antitrypsin deficiency-related mutation in Tunisia.